This paper describes a novel method for the measurement of the permeability of a non-porous poly(dimethylsiloxane) (PDMS) membrane by solid-phase microextraction (SPME). A mathematical model was derived to explain the permeation process and to deduce the equations for calculating the permeability. The effects of feed and permeate gas velocity, membrane module temperature. and humidity on the membrane permeabilities of acetone, benzene, toluene, ethylbenzene, and xylene (BTEX) have been investigated. Permeability measurements of acetone and BTEX through a PDMS membrane have been presented and compared with literature values. A fast, convenient, and calibration-free measurement of the permeability of a PDMS membrane has been demonstrated. (c) 2005 Elsevier B.V. All rights reserved.